The present invention relates to an oxygen and moisture impermeable multilayer barrier film which is free of halogens, and to articles produced therefrom including ostomy bags or pouches and transdermal drug delivery systems.
Plastic film laminates having oxygen and moisture vapor barrier properties are desirable for current packaging requirements, as well as for use in medical applications such as the fabrication of ostomy bags and transdermal drug delivery systems. Where the films are to be used in ostomy applications, they must possess a unique combination of odor and moisture barrier properties as well as low noise, softness, heat or radio-frequency sealability, skin compatibility, and comfort. Such films have been provided in the past through the use of multi-ply film laminates where at least one of the plies is oxygen and moisture vapor impermeable. Typically, the barrier layer in these films comprises a halogen-containing polymer such as chlorinated polyethylene, plasticized polyvinyl chloride, or polyvinylidene chloride copolymers. Others have used multilayered barrier constructions such as ethylene vinyl acetate/polyvinylidene chloride/ethylene vinyl acetate combination films.
While such films have good barrier properties against oxygen, odor, and moisture, one major drawback has been the chlorine content of the films. Such chlorine-containing films are considered to create environmental hazards in their use and disposal in many countries. For example, German Patent No. DD 274,387 describes coextruded composite films for use in the manufacture of colostomy bags having a barrier layer of a copolymer of ethylene and vinyl alcohol and skin layers of a linear low density polyethylene.
Other known multilayer barrier films exist for varied uses including the packaging of meats where oxygen and moisture barrier properties are also important. For example, Lustig et al U.S. Pat. Nos. 5,077,109 and 4,911,963 teach multilayer films using Nylon as the barrier layer with linear low density or very low density polyethylenes as the skin layers. However, such films are taught to be biaxially oriented to improve puncture resistance, making them too noisy for use in ostomy applications.
Accordingly, the need still exists for multilayer barrier films which may be produced by conventional processes without the need for halogen-containing barrier layers and for films which are impermeable to moisture and oxygen, provide odor barrier, softness, and low noise properties, and which have a heat sealable surface for forming ostomy bags or the like.